JP2005142970A - Image processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image processing system capable of separating a document image from a coded image so as to capable of easily applying decode processing to codes. <P>SOLUTION: The image processing system includes: a coding side system 1 for selecting a color including a particular color component related to a prescribed color space and not included in colors used for the document image for a particular color, using the particular color to generate the coded image on the basis of data being an object of coding, composing the coded image with a processing object document and generating a composite document; and a decoding side system 2 for receiving the composite document, extracting the particular color component from the received composite document, separating the coded image from the document image, extracting the coded image, and decoding the extracted coded image to generate data being the coding object. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an image processing system that performs processing related to images such as administrative documents.

  In recent years, various documents have been printed using a printer. These documents include important documents such as official documents such as resident's cards and contracts.

With regard to such highly important documents, it is traditionally guaranteed that the document is original by imprinting a seal or using special paper (in other words, guaranteeing the originality) so that the contents cannot be tampered with later. It was.
JP-A-6-176036 Japanese Patent Laid-Open No. 10-224540

  On the other hand, in recent years, attempts have been made to increase the convenience for users by outputting documents issued by administrative agencies and the like at local branch offices or printers at home. However, in the conventional method described above, since the tampering prevention measure is applied by a method such as stamping or special paper, the above attempt has not been realized specifically.

  Therefore, Patent Document 1 discloses a technique for embedding a document image representing the content of a document and a digital signature in the document using a two-dimensional code. Japanese Patent Application Laid-Open No. 2004-228688 discloses a technique for synthesizing and printing a two-dimensional code obtained by encoding a document content on a document background. According to these, it becomes possible to know the presence or absence of falsification by comparing the document image represented by the two-dimensional code with the contents of the document in which the two-dimensional code is embedded.

  However, when a code (symbol) image is combined with the background of a document (document), a part of the code image may be obscured by the document. In addition, a part of the document content may be mistaken as a code. For this reason, decoding processing becomes difficult, such as lowering the coding rate of the code itself and increasing error correction capability.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an image processing system that can separate an image of a document and a code and can easily decode the code.

  The present invention for solving the problems of the conventional example described above is an image processing system including a code side system and a decoding side system, wherein the code side system includes means for acquiring a document image to be processed. Generating a code image based on the data to be encoded with the specific color as a specific color, which is not included in the color used in the acquired document image and includes a specific color component in a predetermined color space And means for synthesizing the generated code image with the processing target document and generating a synthesized document, wherein the decoding side system receives the synthesized document, and receives the synthesized document from the received synthesized document. Extracting a specific color component included in the specific color to separate a code image and a document image, and extracting the code image; It is characterized in that it comprises means for generating and outputting data as a target of the coding by decoding the out code image.

  The present invention for solving the problems of the conventional example described above is an image processing apparatus for generating a composite document in which a code image is combined with a document image, and includes at least a region to be combined with the code image among the document images. Means for generating a code image based on the data to be encoded with the specific color, with the color including the specific color component relating to the predetermined color space not included in the color used in the part as the specific color And means for synthesizing the generated code image with the synthesis target area of the document image, and generating and outputting a synthesized document.

  The present invention for solving the problems of the conventional example described above is an image processing apparatus for generating a composite document in which a code image is combined with a document image, and one or more of N color components in a predetermined color space. N-1 or less color components are selected, and at least a portion including the synthesis target region of the code image, the document image using at least one color obtained by combining the selected color components alone or mixed. A color component that is not selected at the time of generating the document image as a specific color component, selecting at least one color component including the specific color component, the selected color component alone, Or means for generating a code image based on data to be encoded using at least one specific color obtained by mixing, and the generated code image is converted into the document. Synthesized the synthesis target region of the image, it is characterized in that it comprises means for generating and outputting a composite document, the.

  In these, the synthesis target area may be the entire surface as the background of the document image. Further, here, the document image may be combined with a copy check pattern constituted by using first and second patterns having different appearance modes after copying. Further, the means for generating the code image further includes a copy check pattern formed by using a pattern whose appearance after copying is different from that of the code image in a part of the code image, It is also possible to generate a code image including the copy check pattern.

  Further, the present invention for solving the problems of the conventional example is an image processing method, and a color including a specific color component related to a predetermined color space, which is not included in a color used for a document image to be processed. A specific color, generating a code image based on the data to be encoded with the specific color, and synthesizing the generated code image with the document image to generate and output a composite document. And a process.

  Furthermore, the present invention for solving the problems of the above-described conventional example is an image processing method, wherein 1 to N−1 color components are selected from N color components in a predetermined color space, A step of generating a document image based on the document data to be processed using at least one color obtained by mixing the selected color components singly or by mixture, and selecting at the time of generating the document image Unspecified color component is defined as a specific color component, at least one color component including the specific color component is selected, and the selected color component is encoded using at least one color obtained alone or in combination Generating a code image based on the target data, and synthesizing the generated code image with the document image, generating a synthesized document, and outputting the synthesized document image. It is.

  A recording medium according to one embodiment of the present invention is characterized in that a composite document generated by these image generation methods is formed.

  Furthermore, the program according to an aspect of the present invention allows a computer to specify a color including a specific color component related to a predetermined color space, which is not included in a color used in a document image to be processed, as the specific color, A procedure for generating a code image based on data to be encoded and a procedure for synthesizing the generated code image with the document image, generating a synthesized document, and outputting the synthesized document image are executed. Yes.

  Furthermore, a program according to another aspect of the present invention selects, in a computer, one or more and N−1 or less color components from among N color components related to a predetermined color space, and independently selects the selected color component. Or a procedure for generating a document image based on the document data to be processed using at least one color obtained by mixing or a color component not selected at the time of generating the document image Select at least one color component including the specific color component as a component, and use the at least one color obtained by mixing the selected color component alone or mixed in the data to be encoded. A procedure for generating a code image based on the image, and a step of synthesizing the generated code image with the document image to generate and output a synthesized document. That.

[Embodiment 1]
A first embodiment of the present invention will be described with reference to the drawings. As shown in FIG. 1, the image processing system according to the present embodiment includes a coding side system 1 and a decoding side system 2. Here, the code side system 1 includes an image processing apparatus 10 and an image forming apparatus 20, and the decoding side system 2 includes an image processing apparatus 30 and an image reading apparatus 40.

  As shown in FIG. 2, the image processing apparatus 10 includes a control unit 11, a storage unit 12, an operation unit 13, a display unit 14, and an external interface (I / F) 15. The control unit 11 operates in accordance with a program stored in the storage unit 12, generates a document to be processed, generates a code image related to the generated document, and synthesizes it (synthesized document generation process). Is going. Specific processing contents of the control unit 11 such as the synthetic document generation processing will be described in detail later. Note that these processes may be implemented as printer driver processes for the image forming apparatus 20 executed by the control unit 11.

  The storage unit 12 is a computer-readable recording medium that stores a program executed by the control unit 11. The storage unit 12 also operates as a work memory that stores various data in the processing of the control unit 11.

  The operation unit 13 is a mouse, a keyboard, or the like, accepts a user instruction operation, and outputs the content of the instruction operation to the control unit 11. The display unit 14 is a display that displays an image in accordance with an instruction input from the control unit 11. The external I / F 15 is, for example, a USB (Universal Serial Bus) interface, and in the present embodiment, the image forming apparatus 20 is connected via the external I / F 15.

  The image forming apparatus 20 is a printer, for example, and forms an image on a sheet based on image data input from the image processing apparatus 10.

  The image processing device 30 of the decoding-side system 2 basically has the same configuration as the image processing device 10 of the coding-side system 1, and like the image processing device 10 shown in FIG. The storage unit 32, the operation unit 33, the display unit 34, and an external interface (I / F) 35 are included (not shown), but the contents of processing in the control unit 31 are different. That is, the control unit 31 of the image processing apparatus 30 extracts a code portion from the image data input from the image reading apparatus 40 and performs a decoding process, and a process (authentication) for authenticating the content of the document using the decoding result. Support processing). The specific contents of this authentication support process will be described in detail later.

  The storage unit 32, the operation unit 33, and the display unit 34 are the same as the storage unit 12, the operation unit 13, and the display unit 14 of the image processing apparatus 10, respectively. Further, the external I / F 35 is, for example, a USB (Universal Serial Bus) interface as well as the external I / F 15, except that the image reading device 40 is connected to the external I / F 35.

  The image reading device 40 may be a general scanner, optically reads a document placed on a reading surface, and outputs the read result as image data.

[Processing of control unit 11]
The document to be processed, which is generated by the control unit 11 of the present embodiment, is common to at least one information description column (X1 to X3) and the same type of document as shown in FIG. Information (for example, text) is described in each information description column of form data including included information (hereinafter referred to as fixed information; Y1 to Y5 in FIG. 3). That is, in this type of document, information described in the information description column is variable information, that is, variable information. In the present embodiment, the control unit 11 uses at least a part of the variable information. A code image is generated as a processing target. However, depending on another aspect, image data (document image) obtained by rasterizing a document to be processed may be encoded as it is to generate a code image. Although the control unit 11 generates a document to be processed here, the document to be processed may be acquired from the outside (for example, a server device) via a network or the like.

  Based on the document to be processed (processing target document), the control unit 11 includes information described in each information description column, data related to the description position of each information (position data), and data related to an information display mode. And extract. Since the information described here is generally a text, in the following description, only the text information will be described for the sake of simplicity. However, this information may be an image.

  In addition, the position data related to the description position of the information includes the vertical and horizontal sizes of the information displayed on the processing target document (in the case of text, the vertical and horizontal sizes of the rectangle surrounding the character string image representing the text) and the position coordinates (predetermined coordinate system). The coordinate information of the description position in FIG. The coordinate system representing the position coordinates may be a coordinate system of a predetermined unit such as a point with the lower left corner of the document being (0, 0). Specifically, the position coordinates represent the position of the upper left corner of the rectangle surrounding the character string image. Instead of these, the coordinates of two vertices on the diagonal line of the rectangle on this coordinate system may be used as position data relating to the description position.

  The control unit 11 performs a predetermined encoding process based on the information described in each extracted information description column and the position data regarding the description position of each information, and generates a code image. Here, the encoding method may be one in which text information is expressed in binary. If the code is expressed in binary as described above, a pattern representing “0” (FIG. 4A) and a pattern representing “1” (FIG. 4B) according to the code are displayed as shown in FIG. 4. A two-dimensional code image (FIG. 4C) arranged in a rectangular shape can be obtained. In FIG. 4C, the entire outer periphery is an image (in other words, a synchronization pattern) representing “1”, and is used for the process of specifying the code image portion at the time of decoding.

  The control unit 11 synthesizes the document image and the code image generated based on these documents as follows. First, a code image is repeatedly arranged to generate a background image of a document image, and then one or more and N−1 or less color components are selected from N color components related to a predetermined color space. Here, the color component is a color of any one of the other Ni color components by mixing i color components such as CMY (cyan, magenta, yellow) and RGB (red, green, blue). It may be a set of color components that cannot be reproduced. Here, among the four color components of CMYK (cyan, magenta, yellow, black), among the three color components of CMY, 1 to 2 color components (for example, cyan (C) and magenta (M)) ) Is selected.

  Then, the document image generated based on the document is stored in the storage unit 12 as a bitmap image of a color obtained by any one of the selected color components or a color mixture thereof. Specifically, bitmap images of three planes of CMY may be generated in the storage unit 12, respectively. In this case, the control unit 11 draws a bitmap image as a document image on the C plane and the M plane. Here, for the sake of simplicity, it is assumed that the same image is drawn in C and M, and therefore the document image is a blue image that is a mixture of these images.

  Then, the storage unit 12 selects a color component (in this case, yellow (Y)) that is not used to generate the document image, and selects a color (for example, yellow itself) represented by the selected color component (specific color component). As the specific color, the code image is drawn with the specific color. When the bitmap images of the three CMY planes are respectively generated in the storage unit 12 as described above, the bitmap image that is the code image is drawn on the Y plane.

  Then, the control unit 11 generates a composite document obtained by combining the code image generated in this way and the document image, and ends the processing. An image of a synthesized document obtained by this synthesis is as shown in FIG. As shown in FIG. 5B, which is an enlarged view of a part of FIG. 5A, a part of the code image may be formed so as to overlap a part of the characters constituting the document image. In FIG. 5B, pixels having different colors are represented by different hatching for convenience.

  The control unit 11 outputs the image data of the composite document to the image forming apparatus 20 via the external I / F 15, and the image forming apparatus 20 places the document image as shown in FIG. Form.

  Although an example is shown here in which the document image is formed of cyan and magenta and the code image is formed of yellow, the present invention is not limited to this example. However, the document image is formed with cyan and magenta, and the code image is formed with magenta and yellow, so that they are formed with colors that include at least one color component that is not used to form each other. It is suitable to keep.

[Processing of control unit 31]
Next, processing of the control unit 31 of the image processing device 30 of the decoding side system 2 will be described. The control unit 31 performs processing (authentication support processing) that assists the user in determining whether the content has been tampered with based on image data (combined document reading result) received via the external I / F 35. .

  Specifically, the control unit 31 specifies the code image portion from the image data input from the external I / F 35. The processing for specifying this differs depending on the type of code image, but when a code image as shown in FIG. 4 is used, a synchronous image portion is detected, and a binary image is detected from the code image portion surrounded by the synchronous image. The code represented by is read. One characteristic of the present embodiment is that the control unit 31 at this time uses a specific color component included in the specific color used for forming the code image (as described above, the code image is displayed in one yellow color). In the case of the configuration example, the yellow) is extracted. More specifically, this processing separates the image data into three CMY image planes based on the values of the pixels constituting the image data input from the external I / F 35, and as specific color components, for example, This corresponds to a process of extracting a Y (yellow) plane image as a code image.

  For example, a part of the image of the yellow plane corresponding to the image portion enlarged in FIG. 5B is as shown in FIG.

  And the control part 31 detects a synchronous image part from this extracted code | cord | chord image, reads the code | symbol expressed by the binary from the code | cord | chord image part enclosed by the said synchronous image, and carries out the information encoded. Decrypt. The information encoded here includes the text described in each description column in the processing target document, the vertical and horizontal sizes of each rectangle surrounding the character string image representing each text, and the position coordinates of each rectangle. Including.

  Then, the control unit 31 extracts a document image by extracting a plane of color components (for example, cyan) used for forming the document image. Specifically, a part of the document image (cyan plane image) extracted corresponding to the image portion enlarged in FIG. 5B is as shown in FIG. Then, the following processing shown in FIG. 6 is performed while sequentially selecting each text as an attention text on the extracted document image. First, the control unit 31 secures a storage area for storing an image of the size on the storage unit 32 based on the rectangular vertical and horizontal size data surrounding the character string image corresponding to the text of interest, and stores the storage area in the storage area. The attention text is drawn (S1).

  Next, the control unit 31 extracts a partial image of a rectangular area defined by the position coordinates and size data of the rectangle corresponding to the text of interest from the image data input from the external I / F 35 (S2). . The control unit 31 generates a difference image between the extracted partial image and the image obtained by the drawing in the process S1 (S3). The difference image here is an emphasis expression (for example, represented by a red pixel) where the corresponding pixels are different from each other between the partial image extracted in step S2 and the image obtained by the drawing in step S1. Etc.) can be generated.

  Further, the control unit 31 checks whether or not there is a text that is not a noticed text (S4), and if there is such a text, selects one of them as the next noticed text (S5), It returns to process S1 and continues a process.

  If there is no text that is not the text of interest in process S4 (that is, if all texts have been processed), the difference image generated for each text is displayed on the display unit 34, and the process ends.

  The user refers to the difference image of each text displayed on the display unit 34, and determines that the tampering has been performed when it is recognized that there is a difference due to the highlighted pixel (for example, a red pixel). become able to.

  In the description so far, the coordinate information in the document is used as the position data representing the description position of the information. However, data for identifying the form may be used instead of such data. In other words, when the document to be processed is a predetermined form (format) or one of a plurality of form candidates, the data for identifying the form of the document to be processed is used for each description column. Position data can be specified.

  In this case, the control unit 11 of the image processing apparatus 10 extracts the information described in each information description column based on the processing target document, the information (text) described in each extracted information description column, A predetermined encoding process is performed based on the form identification information for identifying the form of the document to be processed, and a code image is generated. Here, the information described in each information description field may be arranged in a predetermined order (for example, the order of the identifiers in the description field), or is associated with the identifier in the corresponding description field and used for the encoding process. May be.

  Further, as shown in FIG. 7, the storage unit 32 of the image processing apparatus 30 of the decoding-side system 2 stores, in advance, position data and attribute data indicating the position of the description column included in the form for the form identification information. Stores the associated database. Here, the position data of the description field is obtained by associating the identifier of the description field with the coordinate information defining the description field on the composite document. For example, if the description field is a rectangle, the upper left corner and the lower right corner of the rectangle. Coordinate information. The attribute data is data relating to the display form of the text drawn in the description field, and is, for example, the font type, font size, font shape (italic etc.), and arrangement position (left-justified, centering, etc.) with respect to the description field. .

  The control unit 31 extracts the form identification information from the read code, and retrieves and acquires the position data of the description column associated with the form identification information from the database. Then, as in the processing shown in FIG. 6, the control unit 31 sequentially selects information such as text read from the code image as attention information, and describes an image corresponding to the attention information on the storage unit 32. With reference to the position data in the description field, a storage area for storing an image of the size of the description field is secured, and attention information is drawn in the storage area according to the set attribute data.

  Next, the control unit 31 includes a description column (the order in which the attention information is included or the order in which the attention information is included) in which the image corresponding to the attention information is described among the image data input from the external I / F 35. For example, the partial image of the rectangular area defined by the position data of the corresponding description field can be specified by the identifier or the like of the description field is extracted. And the control part 31 produces | generates the difference image of this extracted partial image and the image obtained by drawing by process S1. The control unit 31 repeats this process for each piece of information, and displays the difference image generated for each piece of information on the display unit 34.

  Further, as described above, when comparison based on an image is performed in the decoding side system, it is preferable that data relating to a display mode of information is included as information to be encoded. Here, the display mode of information is the display mode of the character string if it is text. For example, font data (font type, shape (separate italic, bold, etc.), size used for drawing the character string Etc.). When form identification information (which identifies the position of each description field) is used as data representing the description position of the information, a character string in each description field included in the form identified by the form identification information. Data such as left-handed, centering, right-handed, etc. may be included as data relating to the display mode of information.

  In this case, the decoding-side system 2 refers to the font data and arrangement state data when drawing the information (here, text) obtained as the decoding result in the area secured in the storage unit 32. Then, drawing is performed according to these data.

  In the above description, the code image is generated based on the information extracted from each information description field included in the processing target document. However, for example, the information description field for extracting the information that is the source of the code image is set as the user. May be specified.

  In this case, after generating the processing target document, the control unit 11 of the image processing apparatus 10 displays the generated processing target document on the display unit 14, and among the information description fields included in the processing target document, the code A selection operation of an information description column for extracting information that is the basis of an image is received from the user via the operation unit 13. Since this process is the same as the process of selecting a predetermined part in the image displayed on the screen by operating the mouse, a detailed description of the process content is omitted.

  Then, the control unit 11 extracts information included in the selected information description field, and encodes the extracted information and position data related to the description position of the information to generate a code image. Then, the control unit 11 generates a synthesized document by synthesizing the document to be processed. Here, instead of selecting the information description column, a character string portion may be selected.

  In addition, in the difference image generation by the control unit 31, the number of corresponding pixels different from each other is calculated while shifting the corresponding positions of the two image data to be compared, and the comparison result at the corresponding position where the number is the minimum May be generated as a difference image.

  Further, here, as the processing of the decoding side system 2, after drawing an image based on the text obtained by decoding the code image, the drawn image is compared with the corresponding portion of the read image to obtain a difference image Has been made to facilitate authentication such as the determination of whether or not tampering has occurred, but OCR from the text specified by decoding the encoded image and the portion of the read image specified by the description position of the text It may be possible to check the presence or absence of falsification by comparison with text (OCR text) obtained by (optical character recognition).

In addition, the display unit displays an image drawn based on text obtained by simply decoding the code image without generating a difference image, and a partial image corresponding to the drawing position of the text among the read images. 34 may be displayed so that the user can compare.
In addition, a warning message may be displayed to the user only when the generated difference image includes a difference image having a predetermined number of pixels or more.

  As described above, according to the present embodiment, since the code image and the document image are generated and combined in a manner that can be separated by predetermined image processing, the predetermined image processing is performed in the decoding-side system. The image and the document image can be separated. As a result, part of the code image is not obscured by the document image, and decoding of the code does not become difficult.

  In addition, when generating a difference image, the object to be compared with the image generated from the code image is not the read image itself (including the code image), but a restored document image (restored document image, ie, Therefore, the code image portion is not identified as a different portion, and it becomes easy to determine whether or not tampering has occurred.

[Embodiment 2]
Further, in addition to the above-described example, a copy check pattern may be combined with the processing target data. Therefore, a copy check pattern is also combined with the processing target data (as disclosed in JP 2001-346032 A). The same). Therefore, an image processing system according to the second embodiment of the present invention will be described below.

  The image processing system according to the present embodiment has the same configuration as that according to the first embodiment, but the operation of the control unit 11 of the image processing apparatus 10 is slightly different. That is, the control unit 11 according to the present embodiment, as shown in FIG. 3, includes at least one information description field (X1 to X3) and information (hereinafter, fixed) included in the same type of document. A processing target document including Y1 to Y5) in FIG. In this case, instead of the control unit 11 generating the document to be processed, it may be acquired from the outside (for example, a server device).

  The control unit 11 extracts information described in each information description column and data (position data) related to the description position of each information based on the document (processing target document) that is the processing target. Since the information described here is generally a text, in the following description, only the text information will be described for the sake of simplicity. However, this information may be an image.

  In addition, the position data related to the description position of the information includes the vertical and horizontal sizes of the information displayed on the processing target document (in the case of text, the vertical and horizontal sizes of the rectangle surrounding the character string image representing the text) and the position coordinates (predetermined coordinate system). The coordinate information of the description position in FIG. Note that the position data has a modification similar to that in the first embodiment.

  The control unit 11 performs a predetermined encoding process based on the information described in each extracted information description column and the position data regarding the description position of each information, and generates a code image. Here, the encoding method may be one in which text information is expressed in binary. If the code is expressed in binary as described above, a pattern representing “0” (FIG. 4A) and a pattern representing “1” (FIG. 4B) according to the code are displayed as shown in FIG. 4. A two-dimensional code image (FIG. 4C) arranged in a rectangular shape can be obtained. In FIG. 4C, the entire outer periphery is a pattern (in other words, a synchronous pattern) representing “1”, and is used for the process of specifying the code image portion at the time of decoding.

  Further, the control unit 11 according to the present embodiment generates an image in which the code images are repeatedly arranged, replaces a part of the image of each code with a pattern (latent image pattern) as shown in FIG. It is arranged so as to be included in the code image so that a character string or image designated by the user in advance can be represented by the image pattern. The latent image pattern shown in FIG. 8 is composed of isolated points, and the character string portion formed by the latent image pattern does not appear after copying, while in FIGS. 4 (a) and 4 (b). Since the portion described by the code pattern shown appears even after copying, a whitened image emerges according to the latent image pattern shown in FIG. 4A and 4B and the latent image pattern shown in FIG. 8 have the same print density on the paper (for example, it is lit). Keep the same number of pixels (black pixels)).

  When the image arranged in this way (hereinafter referred to as copy check background image) is enlarged, as shown in FIG. 9, a character composed of a latent image pattern in a part of the code pattern (right half side in FIG. 9). The letter “C” in FIG. For reference, FIG. 9 shows a result of synthesizing characters described in the document to be processed (here, the character string “Taro Yamada”).

  Then, as in the first embodiment, the control unit 11 synthesizes the document image generated based on the document and the copy check background image as follows. First, 1 to N−1 color components, for example, cyan (C) and yellow (Y) in the CMY color space are selected from the N color components related to the predetermined color space.

  Then, the document image generated based on the document is stored in the storage unit 12 as a bitmap image using the selected color component. Specifically, when generating bitmap images of three CMY planes in the storage unit 12, the control unit 11 draws bitmap images to be document images on the C plane and the Y plane. At this time, the document image becomes green.

  Then, the storage unit 12 selects a color component (magenta (M) here) that is not used to generate the document image, and selects a color (for example, magenta itself) represented by the selected color component (specific color component). As a specific color, a copy check background image is drawn with the specific color. When the bitmap images of the three CMY planes are respectively generated in the storage unit 12 as described above, a bitmap image serving as a copy restraint background image is drawn on the M plane.

  Then, the control unit 11 generates a composite document by combining the copy check background image generated in this way and the document image, and ends the processing. An image of a synthesized document obtained by this synthesis is as shown in FIG. 10A (FIG. 9 is an enlarged view of a part of FIG. 10A).

  The control unit 11 outputs the image data of the composite document to the image forming apparatus 20 via the external I / F 15, and the image forming apparatus 20 puts the document image as shown in FIG. Form.

  Although an example is shown here in which the document image is formed of cyan and yellow and the copy check background image is formed of magenta, the present invention is not limited to this example. However, the document image is formed of cyan and magenta, and the copy check background image is formed of magenta and yellow. For example, the document image is formed by a color including at least one color component that is not used for forming each other. It is preferable to do so. Here, in order for the copy check background image to function well, it is desirable that the color components of the copy check background image include cyan and magenta having a high density. Further, it is desirable to use a color component other than black (K) for the document image.

  The control unit 11 outputs the image data of the composite document to the image forming apparatus 20 via the external I / F 15, and the image forming apparatus 20 forms an image of the document as shown in FIG. Further, when the sheet on which the composite document shown in FIG. 10A is formed is copied, the latent image pattern portion is whitened as shown in FIG. 10B and embedded as a latent image. A rare image appears.

[Processing of control unit 31]
Next, the operation of the control unit 31 of the decoding-side system 2 that has received the image data as the result of reading this composite document will be described. The control unit 31 extracts a specific color component included in the specific color used for forming the copy check background image (as described above, in the case of an example in which the code image is composed of one yellow color, this yellow). More specifically, this processing separates the image data into three CMY image planes based on the values of the pixels constituting the image data input from the external I / F 35, and as specific color components, for example, This corresponds to a process of extracting a Y (yellow) plane image as a copy check background image. Then, the control unit 31 extracts each of the code image portions (regions separated by the synchronization image) from the extracted copy check background image. Then, the information represented by each pattern including the extracted code image portion is decoded.

  Further, the control unit 31 extracts the color component (for example, cyan) plane used for forming the document image to extract the document image, and uses the information obtained by the decoding and the extracted document image. Thereafter, the same processing as that shown in FIG. 6 of the first embodiment is performed.

[Another example of compositing a copy check pattern]
Also, here, the code pattern as the pattern portion that appears after copying is used as the copy check pattern, and the copy check background image is formed including the latent image pattern constituting the code check pattern. However, instead of this, a copy check pattern may be transparently combined with the document image, and a code image may be combined.

  In this case, the control unit 11 generates a copy check pattern according to a program functionally shown in FIG. That is, as functionally shown in FIG. 11, the process of generating the copy check pattern includes the gray image generation unit 41, the gradation correction unit 42, the error diffusion unit 43, the dither processing unit 44, and the selection unit 45. A latent image generation unit 46, a camouflage pattern generation unit 47, and a synthesis unit 48.

  The gray image generation unit 41 receives an input of the gradation value setting of the gray image to be an embedded image, and generates a gray image of a predetermined size including pixels of the set gradation value.

  The tone correction unit 42 performs tone correction of the input gray image according to a preset tone curve, and outputs the image data after the tone correction to the error diffusion unit 43. The tone curve here is set in advance so that the density of the error diffusion image generated by the error diffusion unit 43 and the halftone image generated by the dither processing unit 44 are substantially the same. The error diffusion unit 43 performs error diffusion processing on the image data after the gradation correction, and generates an error diffusion image. The dither processing unit 44 performs a dither process based on the gray image generated by the gray image generation unit 41 to generate a halftone image.

  The selection unit 45 receives an input of the binary latent image generated by the latent image generation unit 46, and determines the error for each pixel of the latent image according to whether or not it represents a black pixel. Either a portion corresponding to the pixel in the diffusion image or a portion corresponding to the pixel in the halftone image is selected and output.

  The latent image generation unit 46 generates and outputs a binary latent image in accordance with predetermined information or an instruction input from the user. The binary latent image is an image in which character strings such as “COPY” are arranged on the entire surface of the paper.

  The camouflage pattern generation unit 47 generates a camouflage pattern drawn with thin lines on the entire surface of the copy check image. In this camouflage pattern, the pattern portion may be drawn with white pixels, and the portion to be the background may be represented with black pixels.

  The synthesizing unit 48 synthesizes the image output from the selecting unit 45 and the camouflage pattern generated by the camouflage pattern generating unit 47. Specifically, the synthesizing unit 48 calculates a logical product of images to be synthesized. Here, when the camouflage pattern is drawn with white pixels and the portion to be the background is represented with black pixels, the camouflage pattern portion is extracted from the image output from the selection unit 45 by such logical product. A white-out image is obtained. The combining unit 48 outputs the combined image as a copy check pattern.

  The control unit 11 separately generates a code image by the method shown in the first embodiment, transparently synthesizes the copy check pattern and the code image, and further transparently synthesizes the document to be processed with this as a background. To do. As conceptually shown in FIG. 12, “transparent composition” means that the pixel value of an image to be synthesized is used as it is for a portion of an image to be synthesized having a pixel value of a predetermined value (for example, a white pixel). This is a synthesis method to maintain, specifically a synthesis method such as calculating a logical sum of pixels.

  At this time, the control unit 11 first selects 1 to N−1 color components, for example, cyan (C) and magenta (M) in the CMY color space among the N color components related to the predetermined color space. Then, the document image and the copy check pattern are stored in the storage unit 12 as a bitmap image using the selected color component. Specifically, when generating bitmap images of three CMY planes in the storage unit 12, the control unit 11 draws bitmap images as document images on the C plane and the M plane. At this time, the document image and the copy check pattern are blue.

  The storage unit 12 selects a color component (here, yellow (Y)) that is not used for generating a document image or the like, and a color (for example, yellow itself) represented by the selected color component (specific color component). Is used as a specific color, and a code image is drawn with the specific color. When the bitmap images of the three CMY planes are respectively generated in the storage unit 12 as described above, the bitmap image that is the code image is drawn on the Y plane.

  If a part of the image of the composite document generated in this way is enlarged, it will be as shown in FIG. The control unit 11 outputs the composite document image to the image forming apparatus 20 to form it on the paper.

  In this case as well, in the decoding-side system 2 that has received the composite document image, the yellow (Y) image and the other (for example, cyan (C)) image are separated so that the code image can be easily obtained. It can be decrypted.

  Further, in this case, a copy check pattern is included in the cyan (C) image obtained by the separation. Therefore, processing for removing the copy check pattern may be performed as follows. That is, so-called isolated point removal processing is performed to remove a block of pixels having a predetermined size or less from cyan (C) image data. As a result, the error diffusion image pattern and the dither image pattern (first and second patterns) constituting the copy check pattern are removed.

  Further, when these three images are combined, the copy check image may be formed with cyan (C), the document image may be formed with magenta (M), and the code image may be formed with yellow (Y). In addition, it is preferable that the image embedded as a latent image in the copy check pattern can be changed according to designation by the user.

[Modification]
Further, in the description through the first and second embodiments so far, the target region (compositing target region) for synthesizing the code image has been described as the entire background as the background of the document image. The compositing target area may be a part of the document image. In this case, the control unit 11 selects from 1 to N−1 color components (for example, cyan (C) and magenta (M) in the CMY color space) selected from the N color components related to the predetermined color space. Is used to generate an image of a part corresponding to the composition target area in the document image, and for the part other than the part of the document image, for example, black (K) is used or the document image is generated. You may make it produce | generate with the color specified by document data.

  The image of each color component of the composite document generated in this way is as shown in FIGS. 14A to 14D, for example. That is, in this example, the copy check image is formed in cyan (C), and the portion of the code image to be combined in the document image is formed in blue (cyan (C) and magenta (M)). The other parts of the image are formed of black (K), and the code image is formed of yellow (Y).

  Further, the description has been made on the assumption that the image processing device 30 of the decoding-side system 2 is a single device. However, as shown in FIG. 15, the system includes a server device 50 and the image processing device. 10 may store the processing target document in a data storage (not shown) in the server device 50. In this case, the image processing apparatus 10 issues a unique identifier for each generated processing target document, and stores the identifier and the processing target document in the server device 50 in association with each other. In addition, the control unit 11 of the image processing apparatus 10 encodes the identifier, and synthesizes it with the processing target document by including it in the encoded image.

  Further, as processing related to decoding and collation support, a method for performing collation support processing on the server device 50 side, and the server device 50 provides a document to be processed to the decryption side system 2 so that the decryption side system 2 Since there is a method for performing processing for supporting collation, each will be described separately.

  First, when processing for supporting collation is performed on the server device 50 side, the control unit 11 of the decoding-side system 2 sends the read image data to the server device 50 side to request collation. The server device 50 extracts a code image portion from the image data, and decodes information encoded as a code image. Then, based on the information (including the identifier of the processing target document) obtained as a result of the decoding, the corresponding processing target document is extracted from the data storage, and a difference image between the processing target document and the received image data Is transmitted to the decoding side system 2, and the control unit 31 of the decoding side system 2 displays and outputs the difference image on the display unit 34.

  Note that an image generated on the server device 50 side based on text obtained as a result of decoding and position data related to the description position may also be used.

  Next, a method for performing processing for supporting collation in the decoding-side system 2 will be described. In this case, when receiving the input of the image data read by the image reading device 40, the image processing device 30 of the decoding-side system 2 detects the code image portion from the image data, and processes the target document included in the code image. Is sent to the server device 50 to request a document to be processed. In response to the request from the decryption side system 2, the server device 50 provides the requested processing target document to the decryption side system 2.

  Then, the decoding system 2 receives the processing target document received from the server device 50 and the text generated as a result of decoding based on the encoded image and the image generated by the control unit 31 based on the position data regarding the description position. Using this, a difference image is generated, and this difference image is displayed and output on the display unit 34.

  Further, when communication with the server device 50 is not possible, the decoding-side system 2 may generate a difference image itself (by the processing shown in FIG. 6 or the like). Further, when tampering is detected by the difference image obtained from the information from the server device 50 side, the user himself / herself (by the process shown in FIG. 6) generates a difference image so that the presence / absence of tampering can be confirmed. You may keep it.

  In addition, even when using any of these methods, it is preferable to encrypt the communication path among the encoding side system 1, the decoding side system 2, and the server device 50.

  In the above-described first and second embodiments, the image processing apparatus 10 and the image forming apparatus 20 are described as separate apparatuses. However, the image processing apparatus 10 performs image formation. It may be configured integrally with the device 20. In this case, an input of a processing target document is received from an external device such as a personal computer, and composite document generation processing is performed. At this time, the display unit 14 and the operation unit 13 are not necessarily required.

  Furthermore, the image processing apparatus 10 of the encoding side system 1 and the image processing apparatus 30 of the decoding side system 2 may be integrated. For example, the systems according to the first and second embodiments of the present invention can be implemented as a multi-function peripheral that integrally includes the image processing apparatus 10, the image forming apparatus 20, the image processing apparatus 30, and the image reading apparatus 40.

  In addition, when the code image is repeatedly formed when the code image is decoded, each code is determined while comparing the corresponding codes with respect to each of the plurality of code image portions. It is good. Thereby, the decoding accuracy can be improved.

  Furthermore, in the above description, the information that is the basis of the code image is generated based on the document, but this information may be other information.

1 is a configuration block diagram illustrating an example of an image processing system according to an embodiment of the present invention. It is a block diagram showing an example of an image processing apparatus. It is explanatory drawing showing the example of a format of a process target document. It is explanatory drawing showing the example of a code image. It is explanatory drawing showing the example of a synthetic | combination document. It is a flowchart figure showing the example of a process by the side of decoding. It is explanatory drawing showing the example for the specification of the position data using form identification information. It is explanatory drawing showing the example of the pattern which comprises a copy check pattern. It is explanatory drawing showing the partial expansion state of the synthetic document which included the copy check pattern in the code image. It is explanatory drawing showing the example of the synthetic | combination document which included the copy check pattern in the code | symbol image, and its copy result. It is a functional block diagram showing the example of a process for producing | generating a copy check pattern. It is explanatory drawing showing the example of a synthetic | combination process. It is explanatory drawing showing the partial expansion state of the synthetic | combination document by the example which synthesize | combined the copy check pattern and the code | symbol image. It is explanatory drawing showing the example which synthesize | combined the code image part with a part of process target document. It is a block diagram showing another example of the image processing system according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Code | symbol side system, 2 Decoding side system, 10,30 Image processing apparatus, 20 Image forming apparatus, 40 Image reading apparatus, 11,31 Control part, 12,32 Storage part, 13,33 Operation part, 14,34 Display part 15, 35 External interface, 41 Gray image generation unit, 42 Gradation correction unit, 43 Error diffusion unit, 44 Dither processing unit, 45 Selection unit, 46 Latent image image generation unit, 47 Camouflage pattern generation unit, 48 Synthesis unit, 50 server device.

Claims (10)

An image processing system including a coding side system and a decoding side system,
The code side system is:
Means for obtaining a document image to be processed;
Generate a code image based on the data to be encoded with the specific color, with the color including the specific color component in the predetermined color space not included in the color used in the acquired document image as the specific color. Means,
Means for synthesizing the generated code image with the processing target document and generating a synthesized document;
Including
The decoding side system is:
Means for accepting the composite document;
Means for extracting a specific color component included in the specific color from the received composite document, separating the code image and the document image, and extracting the code image;
Means for decoding the extracted code image and generating and outputting the data to be encoded;
An image processing system comprising: An image processing apparatus for generating a composite document obtained by combining a code image with a document image,
Of the document image, a color including a specific color component related to a predetermined color space, which is not included in a color used in at least a portion including a synthesis target area of the code image, is specified as a specific color, Means for generating a code image based on the data to be converted,
Means for synthesizing the generated code image with the synthesis target region of the document image, generating a synthesized document, and outputting the synthesized document;
An image processing apparatus comprising: An image processing apparatus for generating a composite document obtained by combining a code image with a document image,
Of the N color components related to the predetermined color space, one or more and N−1 or less color components are selected, and at least a portion including the synthesis target region of the code image, the selected color component is used alone. Or means for generating a document image using at least one color obtained by mixing;
A color component that is not selected at the time of generating the document image is set as a specific color component, and at least one color component including the specific color component is selected, and the selected color component is obtained alone or in combination. Means for generating a code image based on the data to be encoded using at least one specific color;
Means for synthesizing the generated code image with the synthesis target region of the document image, generating a synthesized document, and outputting the synthesized document;
An image processing apparatus comprising: The image processing apparatus according to claim 2 or 3,
An image processing apparatus, wherein a copy check pattern configured using first and second patterns having different appearance modes after copying is combined with the document image. The image processing apparatus according to claim 2 or 3,
The means for generating the code image further includes a copy check pattern in which a part of the code image includes a pattern whose appearance after copying is different from that of the code image, and uses the specific color. An image processing apparatus that generates a code image including the copy check pattern. Generates a code image based on the data to be encoded with the specific color, with the color including the specific color component in the predetermined color space not included in the color used for the document image to be processed. And a process of
Synthesizing the generated code image with the document image, generating and outputting a synthesized document;
An image generation method comprising: Using at least one color obtained by selecting one or more and N−1 or less color components from among N color components in a predetermined color space, and independently or by mixing the selected color components, Generating a document image based on the document data to be processed;
A color component that is not selected at the time of generating the document image is set as a specific color component, and at least one color component including the specific color component is selected, and the selected color component is obtained alone or in combination. Generating a code image based on the data to be encoded using at least one color;
Synthesizing the generated code image with the document image, generating and outputting a synthesized document;
An image generation method comprising:   A recording medium on which a composite document generated by the image generation method according to claim 6 is formed. On the computer,
Generates a code image based on the data to be encoded with the specific color, with the color including the specific color component in the predetermined color space not included in the color used for the document image to be processed. And the steps to
A procedure of synthesizing the generated code image with the document image, generating a synthesized document, and outputting;
A program characterized by having executed. On the computer,
Using at least one color obtained by selecting one or more and N−1 or less color components from among N color components in a predetermined color space, and independently or by mixing the selected color components, A procedure for generating a document image based on the document data to be processed;
A color component that is not selected at the time of generating the document image is set as a specific color component, and at least one color component including the specific color component is selected, and the selected color component is obtained alone or in combination. A procedure for generating a code image based on data to be encoded using at least one color;
A procedure of synthesizing the generated code image with the document image, generating a synthesized document, and outputting;
A program characterized by having executed.

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